The Strong Perennial Vision: A Critical Review

摘要

The environmental damage associated with the cultivation of annual cereal crops has prompted an interest in perennial alternatives. A distinction can be made between weaker and stronger variants of this perennial vision, the latter suggesting that perenniality imposes no intrinsic yield penalty, including amongst staple cereal crops. This article provides a critical review of this strong perennial vision, arguing that it overemphasizes the capacity of human plant breeding to overcome intrinsic ecological limitations in the life history, reproductive effort, and physiology of perennial crops, and inadequately specifies the nature of the tradeoffs in sexual allocation, nutrient response, leaf economics, and agroecosystem management that have resulted in an annual-dominated agriculture. The benefits of a weaker "perennial vision" that places greater emphasis on addressing environmental problems as social problems of human ecology are discussed.